Functional Overview
This chapter provides the overview of the features offered by the SHFLI Lock-in Amplifier. The first section contains the description of the functional diagram, and the hardware and software feature list. The following section details the front panel and the back panel of the measurement instrument. The last section provides product selection and ordering support.
Features
The SHFLI Lock-in Amplifier consists of several internal units that process digital data (light blue color) and several interface units processing analog signals (dark blue color). The front panel is depicted on the left-hand side and the back panel is depicted on the right-hand side. The arrows between the panels and the interface units indicate selected physical connections and the data flow.
The orange blocks are optional units that can be either ordered at purchase or upgraded later. The SHFLI Lock-in Amplifier has 2 physical channels each with its own signal input and output, auxiliary input and digital inputs and outputs. The ordering guide details the currently available upgrade options.
The signal to be measured is usually connected to one of the two SHFLI signal inputs where it is amplified to a defined range and mixed down to an intermediate frequency (IF) through a double-superheterodyne scheme and digitized at very high speed if above 800 MHz, or directly digitized if below this frequency threshold. The resulting samples are fed into the digital signal processor that contains 8 dual-phase demodulators. The results of the demodulation are fed into a digital interface to be transferred to the host computer through the LAN or USB interface, and can also be routed to the auxiliary outputs on the front panel of the SHFLI. Two low-distortion signal outputs provide the signal generator functionality.
The numerical oscillators generate sine and cosine pairs that are used for the demodulation of the input signal and also for the generation of the SHFLI output signals. For this purpose, when the SHFLI-MF Multi-Frequency option is present, the Output Adder can generate a linear combination of the oscillator outputs to generate a multi-frequency output signal. After the digital-to-analog conversion, the output signal is either routed directly to the output connectors, if its final frequency is below 800 MHz, or through the double-superheterodyne upconversion path if its final frequency needs to be above this frequency.
Hardware trigger and reference signals are used for various purposes inside the instrument, such as triggering demodulation and oscilloscope data acquisition, to acquire or generate an external reference signal, or triggering other equipment.
Lock-in Operating Modes
-
Internal reference mode
-
External reference mode (coming later in 2023)
-
Dual-lock-in operation (two independent lock-in amplifiers in the same box)
-
Triple-harmonic mode (simultaneous measurement at three frequencies within the measurement window that are harmonic of the Numerical Oscillator frequency)
-
Arbitrary frequency mode (with SHFLI-MF option, simultaneous measurement at up to eight arbitrary frequencies within the measurement window)
Super-high-frequency Signal Inputs
-
2 low-noise SHF Inputs, DC - 8.5 GHz frequency range, 1 GHz bandwidth
-
Variable input range, selectable from 1 mV to 1 V peak (10 mV to 1 V in Baseband)
-
Selectable AC/DC coupling in Baseband
Super-high-frequency Signal Outputs
-
Low-noise SHF Outputs, DC - 8.5 GHz frequency range, 1 GHz bandwidth
-
Variable output range, selectable from 10 mV to 1 V peak (10 mV to 0.5 V in Baseband)
Demodulators & Reference
-
Up to 8 dual-phase demodulators
-
Up to 8 programmable numerical oscillators
-
Up to 2 external reference signals (coming later in 2023)
-
Up to 4 input and up to 4 output trigger signals
-
Individually programmable demodulator filters
-
128-bit internal processing
-
64-bit resolution demodulator sample
-
48-bit internal reference resolution
Auxiliary Input and Outputs
-
4 high-speed auxiliary outputs for user-defined signals, 25 MHz bandwidth, 14 bit
-
4 high-precision auxiliary outputs for user-defined signals, 200 kHz bandwidth, 18 bit
-
2 auxiliary inputs, general purpose
High-speed Connectivity
-
SMA connectors on front and back panel for triggers, signals and external clock
-
USB 3.0 high-speed host interface
-
LAN/Ethernet 1 Gbit/s controller interface
-
DIO: 32-bit digital input-output port
-
Clock input/output connectors (10/100 MHz)
Front Panel Tour
The front panel SMA and BNC connectors and control LEDs are arranged as shown in Figure 2 and listed in Table 1.
Position | Label / Name | Description |
---|---|---|
A |
Aux In |
analog Auxiliary Input, max. 10 V |
B |
Signal Output |
single-ended analog Signal Output, DC-8.5 GHz, max. 1 V peak |
C |
Trig Out |
TTL Trigger Outputs 1 to 4 |
D |
Trig In |
TTL Trigger Inputs 1 to 4 |
E |
Signal Input |
single-ended analog Signal Input, DC-8.5 GHz, max. 1 V peak |
F |
High Precision |
high-precision auxiliary outputs 1 to 4 |
G |
High Speed |
high-speed auxiliary outputs 1 to 4 |
H |
multicolor LEDs |
|
Busy |
unused |
|
Ext. Clock |
|
|
ZSync |
unused |
|
Status |
|
|
J |
|
Power button with incorporated status LED
|
Back Panel Tour
The back panel is the main interface for power, control, service and connectivity to other ZI instruments. Please refer to Figure 3 and Table 2 for the detailed description of the items.
Position | Label / Name | Description |
---|---|---|
A |
Earth ground |
4 mm banana jack connector for earth ground, electrically connected to the chassis and the earth pin of the power inlet |
B |
AC 100 - 240 V |
Power inlet, fuse holder, and power switch |
C |
MDS 1 |
SMA: bidirectional TTL ports for multi-device synchronization |
D |
MDS 2 |
SMA: bidirectional TTL ports for multi-device synchronization |
E |
USB 1 |
Universal Serial Bus (USB) 3.0 port for instrument control |
F |
LAN 1GbE |
1 Gbit LAN connector for instrument control |
G |
DIO 32bit |
32-bit digital input/output (DIO) connector |
H |
USB 2 |
Universal Serial Bus (USB) 3.0 port connector → do not use for standard operation |
I |
ZSync Secondary |
unused Attention: This is not an Ethernet plug, connection to an Ethernet network might damage the instrument. |
J |
ZSync Primary |
unused Attention: This is not an Ethernet plug, connection to an Ethernet network might damage the instrument. |
K |
External Clk In |
external clock Input (10 MHz/100 MHz) for synchronization with other instruments |
L |
External Clk Out |
external clock Output (10 MHz/100 MHz) for synchronization with other instruments |
Ordering Guide
Table 3 provides an overview of the available SHFLI products. Upgradeable features are options that can be purchased anytime without the need to send the Instrument back to Zurich Instruments.
Product code | Product name | Description | Field upgrade possible |
---|---|---|---|
SHFLI |
SHFLI Lock-in Amplifier |
base lock-in amplifier |
- |
SHFLI-MF |
SHFLI-MF Multi-frequency |
option |
yes |
SHFLI-MOD |
SHFLI-MOD AM/FM Modulation |
option |
yes1,2 |
SHFLI-PID |
SHFLI-PID Quad PID/PLL Controller |
option |
yes2 |
1 Requires SHFLI-MF Multi-frequency option
2 Available by end of 2023
Feature | SHFLI | SHFLI + SHFLI-MF | SHFLI + SHFLI-PID | SHFLI + SHFLI-MF + SHFLI-PID |
---|---|---|---|---|
Internal reference mode |
yes |
yes |
yes |
yes |
External reference mode1 |
yes |
yes |
yes |
yes |
Dual-channel operation (2 independent measurement units) |
yes |
yes |
yes |
yes |
Signal generators |
2 |
2 |
2 |
2 |
Superposed output sinusoidals per generator |
1 |
up to 8 |
1 |
up to 8 |
Triple-harmonic mode |
yes |
yes |
yes |
yes |
Multi-frequency mode |
- |
yes |
- |
yes |
Arbitrary frequency mode |
- |
yes |
- |
yes |
Number of demodulators |
8 |
8 |
8 |
8 |
Simultaneous frequencies |
2 |
8 |
2 |
8 |
Simultaneous numerical oscillator harmonics |
4+4 |
- |
4+4 |
- |
External references |
2 |
2 |
2 |
2 |
PID controllers |
- |
- |
4 |
4 |
Dynamic reserve |
100 dB |
100 dB |
100 dB |
100 dB |
Lock-in range |
8.5 GHz |
8.5 GHz |
8.5 GHz |
8.5 GHz |
USB 3.0 |
yes |
yes |
yes |
yes |
LAN 1 Gbit/s |
yes |
yes |
yes |
yes |
1 Available by end of 2023